source: libcfa/src/collections/string_res.cfa@ f54e6ec

Last change on this file since f54e6ec was 55b060d, checked in by Peter A. Buhr <pabuhr@…>, 2 years ago

rename directories containers to collections
  • Property mode set to 100644
File size: 39.5 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// string_res -- variable-length, mutable run of text, with resource semantics
8//
9// Author : Michael L. Brooks
10// Created On : Fri Sep 03 11:00:00 2021
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Mon Aug 14 18:06:01 2023
13// Update Count : 12
14//
15
16#include "string_res.hfa"
17#include "string_sharectx.hfa"
18#include "stdlib.hfa"
19#include <ctype.h>
20
21// Workaround for observed performance penalty from calling CFA's alloc.
22// Workaround is: EndVbyte = TEMP_ALLOC(char, CurrSize)
23// Should be: EndVbyte = alloc(CurrSize)
24#define TEMP_ALLOC(T, n) (( T* ) malloc( n * sizeof( T ) ))
25
26#include <assert.h>
27
28//######################### VbyteHeap "header" #########################
29
30#ifdef VbyteDebug
31HandleNode *HeaderPtr;
32#endif // VbyteDebug
33
34struct VbyteHeap {
35
36 int NoOfCompactions; // number of compactions of the byte area
37 int NoOfExtensions; // number of extensions in the size of the byte area
38 int NoOfReductions; // number of reductions in the size of the byte area
39
40 int InitSize; // initial number of bytes in the byte-string area
41 int CurrSize; // current number of bytes in the byte-string area
42 char *StartVbyte; // pointer to the `st byte of the start of the byte-string area
43 char *EndVbyte; // pointer to the next byte after the end of the currently used portion of byte-string area
44 void *ExtVbyte; // pointer to the next byte after the end of the byte-string area
45
46 HandleNode Header; // header node for handle list
47}; // VbyteHeap
48
49
50static void compaction( VbyteHeap & ); // compaction of the byte area
51static void garbage( VbyteHeap &, int ); // garbage collect the byte area
52static void extend( VbyteHeap &, int ); // extend the size of the byte area
53static void reduce( VbyteHeap &, int ); // reduce the size of the byte area
54
55static void ?{}( VbyteHeap &, size_t = 1000 );
56static void ^?{}( VbyteHeap & );
57
58static int ByteCmp( char *, int, int, char *, int, int ); // compare 2 blocks of bytes
59static char *VbyteAlloc( VbyteHeap &, int ); // allocate a block bytes in the heap
60static char *VbyteTryAdjustLast( VbyteHeap &, int );
61
62static void AddThisAfter( HandleNode &, HandleNode & );
63static void DeleteNode( HandleNode & );
64static void MoveThisAfter( HandleNode &, const HandleNode & ); // move current handle after parameter handle
65
66
67// Allocate the storage for the variable sized area and intialize the heap variables.
68
69static void ?{}( VbyteHeap & this, size_t Size ) with(this) {
70#ifdef VbyteDebug
71 serr | "enter:VbyteHeap::VbyteHeap, this:" | &this | " Size:" | Size;
72#endif // VbyteDebug
73 NoOfCompactions = NoOfExtensions = NoOfReductions = 0;
74 InitSize = CurrSize = Size;
75 StartVbyte = EndVbyte = TEMP_ALLOC(char, CurrSize);
76 ExtVbyte = (void *)( StartVbyte + CurrSize );
77 Header.flink = Header.blink = &Header;
78 Header.ulink = & this;
79#ifdef VbyteDebug
80 HeaderPtr = &Header;
81 serr | "exit:VbyteHeap::VbyteHeap, this:" | &this;
82#endif // VbyteDebug
83} // VbyteHeap
84
85
86// Release the dynamically allocated storage for the byte area.
87
88static void ^?{}( VbyteHeap & this ) with(this) {
89 free( StartVbyte );
90} // ~VbyteHeap
91
92
93//######################### HandleNode #########################
94
95
96// Create a handle node. The handle is not linked into the handle list. This is the responsibilitiy of the handle
97// creator.
98
99static void ?{}( HandleNode & this ) with(this) {
100#ifdef VbyteDebug
101 serr | "enter:HandleNode::HandleNode, this:" | &this;
102#endif // VbyteDebug
103 s = 0;
104 lnth = 0;
105#ifdef VbyteDebug
106 serr | "exit:HandleNode::HandleNode, this:" | &this;
107#endif // VbyteDebug
108} // HandleNode
109
110// Create a handle node. The handle is linked into the handle list at the end. This means that this handle will NOT be
111// in order by string address, but this is not a problem because a string with length zero does nothing during garbage
112// collection.
113
114static void ?{}( HandleNode & this, VbyteHeap & vh ) with(this) {
115#ifdef VbyteDebug
116 serr | "enter:HandleNode::HandleNode, this:" | &this;
117#endif // VbyteDebug
118 s = 0;
119 lnth = 0;
120 ulink = &vh;
121 AddThisAfter( this, *vh.Header.blink );
122#ifdef VbyteDebug
123 serr | "exit:HandleNode::HandleNode, this:" | &this;
124#endif // VbyteDebug
125} // HandleNode
126
127
128// Delete a node from the handle list by unchaining it from the list. If the handle node was allocated dynamically, it
129// is the responsibility of the creator to destroy it.
130
131static void ^?{}( HandleNode & this ) with(this) {
132#ifdef VbyteDebug
133 serr | "enter:HandleNode::~HandleNode, this:" | & this;
134 {
135 serr | nlOff;
136 serr | " lnth:" | lnth | " s:" | (void *)s | ",\"";
137 for ( i; lnth ) {
138 serr | s[i];
139 } // for
140 serr | "\" flink:" | flink | " blink:" | blink | nl;
141 serr | nlOn;
142 }
143#endif // VbyteDebug
144 DeleteNode( this );
145} // ~HandleNode
146
147
148//######################### String Sharing Context #########################
149
150static string_sharectx * ambient_string_sharectx; // fickle top of stack
151static string_sharectx default_string_sharectx = {NEW_SHARING}; // stable bottom of stack
152
153void ?{}( string_sharectx & this, StringSharectx_Mode mode ) with( this ) {
154 (older){ ambient_string_sharectx };
155 if ( mode == NEW_SHARING ) {
156 (activeHeap){ new( (size_t) 1000 ) };
157 } else {
158 verify( mode == NO_SHARING );
159 (activeHeap){ 0p };
160 }
161 ambient_string_sharectx = & this;
162}
163
164void ^?{}( string_sharectx & this ) with( this ) {
165 if ( activeHeap ) delete( activeHeap );
166
167 // unlink this from older-list starting from ambient_string_sharectx
168 // usually, this==ambient_string_sharectx and the loop runs zero times
169 string_sharectx *& c = ambient_string_sharectx;
170 while ( c != &this ) &c = &c->older; // find this
171 c = this.older; // unlink
172}
173
174//######################### String Resource #########################
175
176
177VbyteHeap * DEBUG_string_heap() {
178 assert( ambient_string_sharectx->activeHeap && "No sharing context is active" );
179 return ambient_string_sharectx->activeHeap;
180}
181
182size_t DEBUG_string_bytes_avail_until_gc( VbyteHeap * heap ) {
183 return ((char*)heap->ExtVbyte) - heap->EndVbyte;
184}
185
186size_t DEBUG_string_bytes_in_heap( VbyteHeap * heap ) {
187 return heap->CurrSize;
188}
189
190const char * DEBUG_string_heap_start( VbyteHeap * heap ) {
191 return heap->StartVbyte;
192}
193
194// Returns the size of the string in bytes
195size_t size(const string_res &s) with(s) {
196 return Handle.lnth;
197}
198
199// Output operator
200ofstream & ?|?(ofstream &out, const string_res &s) {
201 // CFA string is NOT null terminated, so print exactly lnth characters in a minimum width of 0.
202 out | wd( 0, s.Handle.lnth, s.Handle.s ) | nonl;
203 return out;
204}
205
206void ?|?(ofstream &out, const string_res &s) {
207 (ofstream &)(out | s); ends( out );
208}
209
210// Input operator
211ifstream & ?|?(ifstream &in, string_res &s) {
212
213 // Reading into a temp before assigning to s is near zero overhead in typical cases because of sharing.
214 // If s is a substring of something larger, simple assignment takes care of that case correctly.
215 // But directly reading a variable amount of text into the middle of a larger context is not practical.
216 string_res temp;
217
218 // Read in chunks. Often, one chunk is enough. Keep the string that accumulates chunks last in the heap,
219 // so available room is rest of heap. When a chunk fills the heap, force growth then take the next chunk.
220 for (;;) {
221 // Append dummy content to temp, forcing expansion when applicable (occurs always on subsequent loops)
222 // length 2 ensures room for at least one real char, plus scanf/pipe-cstr's null terminator
223 temp += "--";
224 assert( temp.Handle.ulink->EndVbyte == temp.Handle.s + temp.Handle.lnth ); // last in heap
225
226 // reset, to overwrite the appended "--"
227 temp.Handle.lnth -= 2;
228 temp.Handle.ulink->EndVbyte -= 2;
229
230 // rest of heap, less 1 byte for null terminator, is available to read into
231 int lenReadable = (char*)temp.Handle.ulink->ExtVbyte - temp.Handle.ulink->EndVbyte - 1;
232 assert (lenReadable >= 1);
233
234 // get bytes
235 in | wdi( lenReadable + 1, lenReadable, temp.Handle.ulink->EndVbyte );
236 int lenWasRead = strlen(temp.Handle.ulink->EndVbyte);
237
238 // update metadata
239 temp.Handle.lnth += lenWasRead;
240 temp.Handle.ulink->EndVbyte += lenWasRead;
241
242 if (lenWasRead < lenReadable) break;
243 }
244
245 s = temp;
246 return in;
247}
248
249
250// Empty constructor
251void ?{}(string_res &s) with(s) {
252 if( ambient_string_sharectx->activeHeap ) {
253 (Handle){ * ambient_string_sharectx->activeHeap };
254 (shareEditSet_owns_ulink){ false };
255 verify( Handle.s == 0p && Handle.lnth == 0 );
256 } else {
257 (Handle){ * new( (size_t) 10 ) }; // TODO: can I lazily avoid allocating for empty string
258 (shareEditSet_owns_ulink){ true };
259 Handle.s = Handle.ulink->StartVbyte;
260 verify( Handle.lnth == 0 );
261 }
262 s.shareEditSet_prev = &s;
263 s.shareEditSet_next = &s;
264}
265
266static void eagerCopyCtorHelper(string_res &s, const char* rhs, size_t rhslnth) with(s) {
267 if( ambient_string_sharectx->activeHeap ) {
268 (Handle){ * ambient_string_sharectx->activeHeap };
269 (shareEditSet_owns_ulink){ false };
270 } else {
271 (Handle){ * new( rhslnth ) };
272 (shareEditSet_owns_ulink){ true };
273 }
274 Handle.s = VbyteAlloc(*Handle.ulink, rhslnth);
275 Handle.lnth = rhslnth;
276 memmove( Handle.s, rhs, rhslnth );
277 s.shareEditSet_prev = &s;
278 s.shareEditSet_next = &s;
279}
280
281// Constructor from a raw buffer and size
282void ?{}(string_res &s, const char* rhs, size_t rhslnth) with(s) {
283 eagerCopyCtorHelper(s, rhs, rhslnth);
284}
285
286// private ctor (not in header): use specified heap (ignore ambient) and copy chars in
287void ?{}( string_res &s, VbyteHeap & heap, const char* rhs, size_t rhslnth ) with(s) {
288 (Handle){ heap };
289 Handle.s = VbyteAlloc(*Handle.ulink, rhslnth);
290 Handle.lnth = rhslnth;
291 (s.shareEditSet_owns_ulink){ false };
292 memmove( Handle.s, rhs, rhslnth );
293 s.shareEditSet_prev = &s;
294 s.shareEditSet_next = &s;
295}
296
297// General copy constructor
298void ?{}(string_res &s, const string_res & s2, StrResInitMode mode, size_t start, size_t end ) {
299
300 verify( start <= end && end <= s2.Handle.lnth );
301
302 if (s2.Handle.ulink != ambient_string_sharectx->activeHeap && mode == COPY_VALUE) {
303 // crossing heaps (including private): copy eagerly
304 eagerCopyCtorHelper(s, s2.Handle.s + start, end - start);
305 verify(s.shareEditSet_prev == &s);
306 verify(s.shareEditSet_next == &s);
307 } else {
308 (s.Handle){};
309 s.Handle.s = s2.Handle.s + start;
310 s.Handle.lnth = end - start;
311 s.Handle.ulink = s2.Handle.ulink;
312
313 AddThisAfter(s.Handle, s2.Handle ); // insert this handle after rhs handle
314 // ^ bug? skip others at early point in string
315
316 if (mode == COPY_VALUE) {
317 verify(s2.Handle.ulink == ambient_string_sharectx->activeHeap);
318 // requested logical copy in same heap: defer copy until write
319
320 (s.shareEditSet_owns_ulink){ false };
321
322 // make s alone in its shareEditSet
323 s.shareEditSet_prev = &s;
324 s.shareEditSet_next = &s;
325 } else {
326 verify( mode == SHARE_EDITS );
327 // sharing edits with source forces same heap as source (ignore context)
328
329 (s.shareEditSet_owns_ulink){ s2.shareEditSet_owns_ulink };
330
331 // s2 is logically const but not implementation const
332 string_res & s2mod = (string_res &) s2;
333
334 // insert s after s2 on shareEditSet
335 s.shareEditSet_next = s2mod.shareEditSet_next;
336 s.shareEditSet_prev = &s2mod;
337 s.shareEditSet_next->shareEditSet_prev = &s;
338 s.shareEditSet_prev->shareEditSet_next = &s;
339 }
340 }
341}
342
343static void assignEditSet(string_res & this, string_res * shareEditSetStartPeer, string_res * shareEditSetEndPeer,
344 char * resultSesStart,
345 size_t resultSesLnth,
346 HandleNode * resultPadPosition, size_t bsize ) {
347
348 char * beforeBegin = shareEditSetStartPeer->Handle.s;
349 size_t beforeLen = this.Handle.s - beforeBegin;
350
351 char * afterBegin = this.Handle.s + this.Handle.lnth;
352 size_t afterLen = shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth - afterBegin;
353
354 size_t oldLnth = this.Handle.lnth;
355
356 this.Handle.s = resultSesStart + beforeLen;
357 this.Handle.lnth = bsize;
358 if (resultPadPosition)
359 MoveThisAfter( this.Handle, *resultPadPosition );
360
361 // adjust all substring string and handle locations, and check if any substring strings are outside the new base string
362 char *limit = resultSesStart + resultSesLnth;
363 for ( string_res * p = this.shareEditSet_next; p != &this; p = p->shareEditSet_next ) {
364 verify (p->Handle.s >= beforeBegin);
365 if ( p->Handle.s >= afterBegin ) {
366 verify ( p->Handle.s <= afterBegin + afterLen );
367 verify ( p->Handle.s + p->Handle.lnth <= afterBegin + afterLen );
368 // p starts after the edit
369 // take start and end as end-anchored
370 size_t startOffsetFromEnd = afterBegin + afterLen - p->Handle.s;
371 p->Handle.s = limit - startOffsetFromEnd;
372 // p->Handle.lnth unaffected
373 } else if ( p->Handle.s <= beforeBegin + beforeLen ) {
374 // p starts before, or at the start of, the edit
375 if ( p->Handle.s + p->Handle.lnth <= beforeBegin + beforeLen ) {
376 // p ends before the edit
377 // take end as start-anchored too
378 // p->Handle.lnth unaffected
379 } else if ( p->Handle.s + p->Handle.lnth < afterBegin ) {
380 // p ends during the edit; p does not include the last character replaced
381 // clip end of p to end at start of edit
382 p->Handle.lnth = beforeLen - ( p->Handle.s - beforeBegin );
383 } else {
384 // p ends after the edit
385 verify ( p->Handle.s + p->Handle.lnth <= afterBegin + afterLen );
386 // take end as end-anchored
387 // stretch-shrink p according to the edit
388 p->Handle.lnth += this.Handle.lnth;
389 p->Handle.lnth -= oldLnth;
390 }
391 // take start as start-anchored
392 size_t startOffsetFromStart = p->Handle.s - beforeBegin;
393 p->Handle.s = resultSesStart + startOffsetFromStart;
394 } else {
395 verify ( p->Handle.s < afterBegin );
396 // p starts during the edit
397 verify( p->Handle.s + p->Handle.lnth >= beforeBegin + beforeLen );
398 if ( p->Handle.s + p->Handle.lnth < afterBegin ) {
399 // p ends during the edit; p does not include the last character replaced
400 // set p to empty string at start of edit
401 p->Handle.s = this.Handle.s;
402 p->Handle.lnth = 0;
403 } else {
404 // p includes the end of the edit
405 // clip start of p to start at end of edit
406 int charsToClip = afterBegin - p->Handle.s;
407 p->Handle.s = this.Handle.s + this.Handle.lnth;
408 p->Handle.lnth -= charsToClip;
409 }
410 }
411 if (resultPadPosition)
412 MoveThisAfter( p->Handle, *resultPadPosition ); // move substring handle to maintain sorted order by string position
413 }
414}
415
416// traverse the share-edit set (SES) to recover the range of a base string to which `this` belongs
417static void locateInShareEditSet( string_res &this, string_res *&shareEditSetStartPeer, string_res *&shareEditSetEndPeer ) {
418 shareEditSetStartPeer = & this;
419 shareEditSetEndPeer = & this;
420 for (string_res * editPeer = this.shareEditSet_next; editPeer != &this; editPeer = editPeer->shareEditSet_next) {
421 if ( editPeer->Handle.s < shareEditSetStartPeer->Handle.s ) {
422 shareEditSetStartPeer = editPeer;
423 }
424 if ( shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth < editPeer->Handle.s + editPeer->Handle.lnth) {
425 shareEditSetEndPeer = editPeer;
426 }
427 }
428}
429
430static string_res & assign_(string_res &this, const char* buffer, size_t bsize, const string_res & valSrc) {
431
432 string_res * shareEditSetStartPeer;
433 string_res * shareEditSetEndPeer;
434 locateInShareEditSet( this, shareEditSetStartPeer, shareEditSetEndPeer );
435
436 verify( shareEditSetEndPeer->Handle.s >= shareEditSetStartPeer->Handle.s );
437 size_t origEditSetLength = shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth - shareEditSetStartPeer->Handle.s;
438 verify( origEditSetLength >= this.Handle.lnth );
439
440 if ( this.shareEditSet_owns_ulink ) { // assigning to private context
441 // ok to overwrite old value within LHS
442 char * prefixStartOrig = shareEditSetStartPeer->Handle.s;
443 int prefixLen = this.Handle.s - prefixStartOrig;
444 char * suffixStartOrig = this.Handle.s + this.Handle.lnth;
445 int suffixLen = shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth - suffixStartOrig;
446
447 int delta = bsize - this.Handle.lnth;
448 if ( char * oldBytes = VbyteTryAdjustLast( *this.Handle.ulink, delta ) ) {
449 // growing: copy from old to new
450 char * dest = VbyteAlloc( *this.Handle.ulink, origEditSetLength + delta );
451 char *destCursor = dest; memcpy(destCursor, prefixStartOrig, prefixLen);
452 destCursor += prefixLen; memcpy(destCursor, buffer , bsize );
453 destCursor += bsize; memcpy(destCursor, suffixStartOrig, suffixLen);
454 assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
455 dest,
456 origEditSetLength + delta,
457 0p, bsize);
458 free( oldBytes );
459 } else {
460 // room is already allocated in-place: bubble suffix and overwite middle
461 memmove( suffixStartOrig + delta, suffixStartOrig, suffixLen );
462 memcpy( this.Handle.s, buffer, bsize );
463
464 assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
465 shareEditSetStartPeer->Handle.s,
466 origEditSetLength + delta,
467 0p, bsize);
468 }
469
470 } else if ( // assigning to shared context
471 this.Handle.lnth == origEditSetLength && // overwriting entire run of SES
472 & valSrc && // sourcing from a managed string
473 valSrc.Handle.ulink == this.Handle.ulink ) { // sourcing from same heap
474
475 // SES's result will only use characters from the source string => reuse source
476 assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
477 valSrc.Handle.s,
478 valSrc.Handle.lnth,
479 &((string_res&)valSrc).Handle, bsize);
480
481 } else {
482 // overwriting a proper substring of some string: mash characters from old and new together (copy on write)
483 // OR we are importing characters: need to copy eagerly (can't refer to source)
484
485 // full string is from start of shareEditSetStartPeer thru end of shareEditSetEndPeer
486 // `this` occurs in the middle of it, to be replaced
487 // build up the new text in `pasting`
488
489 string_res pasting = {
490 * this.Handle.ulink, // maintain same heap, regardless of context
491 shareEditSetStartPeer->Handle.s, // start of SES
492 this.Handle.s - shareEditSetStartPeer->Handle.s }; // length of SES, before this
493 append( pasting,
494 buffer, // start of replacement for this
495 bsize ); // length of replacement for this
496 append( pasting,
497 this.Handle.s + this.Handle.lnth, // start of SES after this
498 shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth -
499 (this.Handle.s + this.Handle.lnth) ); // length of SES, after this
500
501 // The above string building can trigger compaction.
502 // The reference points (that are arguments of the string building) may move during that building.
503 // From this point on, they are stable.
504
505 assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
506 pasting.Handle.s,
507 pasting.Handle.lnth,
508 &pasting.Handle, bsize);
509 }
510
511 return this;
512}
513
514string_res & assign(string_res &this, const char* buffer, size_t bsize) {
515 return assign_(this, buffer, bsize, *0p);
516}
517
518string_res & ?=?(string_res &s, char other) {
519 return assign(s, &other, 1);
520}
521
522// Copy assignment operator
523string_res & ?=?(string_res & this, const string_res & rhs) with( this ) {
524 return assign_(this, rhs.Handle.s, rhs.Handle.lnth, rhs);
525}
526
527string_res & ?=?(string_res & this, string_res & rhs) with( this ) {
528 const string_res & rhs2 = rhs;
529 return this = rhs2;
530}
531
532
533// Destructor
534void ^?{}(string_res &s) with(s) {
535 // much delegated to implied ^VbyteSM
536
537 // sever s from its share-edit peers, if any (four no-ops when already solo)
538 s.shareEditSet_prev->shareEditSet_next = s.shareEditSet_next;
539 s.shareEditSet_next->shareEditSet_prev = s.shareEditSet_prev;
540 // s.shareEditSet_next = &s;
541 // s.shareEditSet_prev = &s;
542
543 if (shareEditSet_owns_ulink && s.shareEditSet_next == &s) { // last one out
544 delete( s.Handle.ulink );
545 }
546}
547
548
549// Returns the character at the given index
550// With unicode support, this may be different from just the byte at the given
551// offset from the start of the string.
552char ?[?](const string_res &s, size_t index) with(s) {
553 //TODO: Check if index is valid (no exceptions yet)
554 return Handle.s[index];
555}
556
557void assignAt(const string_res &s, size_t index, char val) {
558 string_res editZone = { s, SHARE_EDITS, index, index+1 };
559 assign(editZone, &val, 1);
560}
561
562
563///////////////////////////////////////////////////////////////////
564// Concatenation
565
566void append(string_res &str1, const char * buffer, size_t bsize) {
567 size_t clnth = str1.Handle.lnth + bsize;
568 if ( str1.Handle.s + str1.Handle.lnth == buffer ) { // already juxtapose ?
569 // no-op
570 } else { // must copy some text
571 if ( str1.Handle.s + str1.Handle.lnth == VbyteAlloc(*str1.Handle.ulink, 0) ) { // str1 at end of string area ?
572 VbyteAlloc( *str1.Handle.ulink, bsize ); // create room for 2nd part at the end of string area
573 } else { // copy the two parts
574 char * str1newBuf = VbyteAlloc( *str1.Handle.ulink, clnth );
575 char * str1oldBuf = str1.Handle.s; // must read after VbyteAlloc call in case it gs's
576 str1.Handle.s = str1newBuf;
577 memcpy( str1.Handle.s, str1oldBuf, str1.Handle.lnth );
578 } // if
579 memcpy( str1.Handle.s + str1.Handle.lnth, buffer, bsize );
580 } // if
581 str1.Handle.lnth = clnth;
582}
583
584void ?+=?(string_res &str1, const string_res &str2) {
585 append( str1, str2.Handle.s, str2.Handle.lnth );
586}
587
588void ?+=?(string_res &s, char other) {
589 append( s, &other, 1 );
590}
591
592
593
594
595
596//////////////////////////////////////////////////////////
597// Comparisons
598
599
600bool ?==?(const string_res &s1, const string_res &s2) {
601 return ByteCmp( s1.Handle.s, 0, s1.Handle.lnth, s2.Handle.s, 0, s2.Handle.lnth) == 0;
602}
603
604bool ?!=?(const string_res &s1, const string_res &s2) {
605 return !(s1 == s2);
606}
607bool ?==?(const string_res &s, const char* other) {
608 string_res sother = other;
609 return s == sother;
610}
611bool ?!=?(const string_res &s, const char* other) {
612 return !(s == other);
613}
614
615
616//////////////////////////////////////////////////////////
617// Search
618
619bool contains(const string_res &s, char ch) {
620 for ( i; size(s) ) {
621 if (s[i] == ch) return true;
622 }
623 return false;
624}
625
626int find(const string_res &s, char search) {
627 return findFrom(s, 0, search);
628}
629
630int findFrom(const string_res &s, size_t fromPos, char search) {
631 // FIXME: This paricular overload (find of single char) is optimized to use memchr.
632 // The general overload (find of string, memchr applying to its first character) and `contains` should be adjusted to match.
633 char * searchFrom = s.Handle.s + fromPos;
634 size_t searchLnth = s.Handle.lnth - fromPos;
635 int searchVal = search;
636 char * foundAt = (char *) memchr(searchFrom, searchVal, searchLnth);
637 if (foundAt == 0p) return s.Handle.lnth;
638 else return foundAt - s.Handle.s;
639}
640
641int find(const string_res &s, const string_res &search) {
642 return findFrom(s, 0, search);
643}
644
645int findFrom(const string_res &s, size_t fromPos, const string_res &search) {
646 return findFrom(s, fromPos, search.Handle.s, search.Handle.lnth);
647}
648
649int find(const string_res &s, const char* search) {
650 return findFrom(s, 0, search);
651}
652int findFrom(const string_res &s, size_t fromPos, const char* search) {
653 return findFrom(s, fromPos, search, strlen(search));
654}
655
656int find(const string_res &s, const char* search, size_t searchsize) {
657 return findFrom(s, 0, search, searchsize);
658}
659
660int findFrom(const string_res &s, size_t fromPos, const char* search, size_t searchsize) {
661
662 /* Remaining implementations essentially ported from Sunjay's work */
663
664
665 // FIXME: This is a naive algorithm. We probably want to switch to someting
666 // like Boyer-Moore in the future.
667 // https://en.wikipedia.org/wiki/String_searching_algorithm
668
669 // Always find the empty string
670 if (searchsize == 0) {
671 return 0;
672 }
673
674 for ( i; fromPos ~ s.Handle.lnth ) {
675 size_t remaining = s.Handle.lnth - i;
676 // Never going to find the search string if the remaining string is
677 // smaller than search
678 if (remaining < searchsize) {
679 break;
680 }
681
682 bool matched = true;
683 for ( j; searchsize ) {
684 if (search[j] != s.Handle.s[i + j]) {
685 matched = false;
686 break;
687 }
688 }
689 if (matched) {
690 return i;
691 }
692 }
693
694 return s.Handle.lnth;
695}
696
697bool includes(const string_res &s, const string_res &search) {
698 return includes(s, search.Handle.s, search.Handle.lnth);
699}
700
701bool includes(const string_res &s, const char* search) {
702 return includes(s, search, strlen(search));
703}
704
705bool includes(const string_res &s, const char* search, size_t searchsize) {
706 return find(s, search, searchsize) < s.Handle.lnth;
707}
708
709bool startsWith(const string_res &s, const string_res &prefix) {
710 return startsWith(s, prefix.Handle.s, prefix.Handle.lnth);
711}
712
713bool startsWith(const string_res &s, const char* prefix) {
714 return startsWith(s, prefix, strlen(prefix));
715}
716
717bool startsWith(const string_res &s, const char* prefix, size_t prefixsize) {
718 if (s.Handle.lnth < prefixsize) {
719 return false;
720 }
721 return memcmp(s.Handle.s, prefix, prefixsize) == 0;
722}
723
724bool endsWith(const string_res &s, const string_res &suffix) {
725 return endsWith(s, suffix.Handle.s, suffix.Handle.lnth);
726}
727
728bool endsWith(const string_res &s, const char* suffix) {
729 return endsWith(s, suffix, strlen(suffix));
730}
731
732bool endsWith(const string_res &s, const char* suffix, size_t suffixsize) {
733 if (s.Handle.lnth < suffixsize) {
734 return false;
735 }
736 // Amount to offset the bytes pointer so that we are comparing the end of s
737 // to suffix. s.bytes + offset should be the first byte to compare against suffix
738 size_t offset = s.Handle.lnth - suffixsize;
739 return memcmp(s.Handle.s + offset, suffix, suffixsize) == 0;
740}
741
742 /* Back to Mike's work */
743
744
745///////////////////////////////////////////////////////////////////////////
746// charclass, include, exclude
747
748void ?{}( charclass_res & this, const string_res & chars) {
749 (this){ chars.Handle.s, chars.Handle.lnth };
750}
751
752void ?{}( charclass_res & this, const char * chars ) {
753 (this){ chars, strlen(chars) };
754}
755
756void ?{}( charclass_res & this, const char * chars, size_t charssize ) {
757 (this.chars){ chars, charssize };
758 // now sort it ?
759}
760
761void ^?{}( charclass_res & this ) {
762 ^(this.chars){};
763}
764
765static bool test( const charclass_res & mask, char c ) {
766 // instead, use sorted char list?
767 return contains( mask.chars, c );
768}
769
770int exclude(const string_res &s, const charclass_res &mask) {
771 for ( i; size(s) ) {
772 if ( test(mask, s[i]) ) return i;
773 }
774 return size(s);
775}
776
777int include(const string_res &s, const charclass_res &mask) {
778 for ( i; size(s) ) {
779 if ( ! test(mask, s[i]) ) return i;
780 }
781 return size(s);
782}
783
784//######################### VbyteHeap "implementation" #########################
785
786
787// Add a new HandleNode node n after the current HandleNode node.
788
789static void AddThisAfter( HandleNode & this, HandleNode & n ) with(this) {
790#ifdef VbyteDebug
791 serr | "enter:AddThisAfter, this:" | &this | " n:" | &n;
792#endif // VbyteDebug
793 // Performance note: we are on the critical path here. MB has ensured that the verifies don't contribute to runtime (are compiled away, like they're supposed to be).
794 verify( n.ulink != 0p );
795 verify( this.ulink == n.ulink );
796 flink = n.flink;
797 blink = &n;
798 n.flink->blink = &this;
799 n.flink = &this;
800#ifdef VbyteDebug
801 {
802 serr | "HandleList:";
803 serr | nlOff;
804 for ( HandleNode *ni = HeaderPtr->flink; ni != HeaderPtr; ni = ni->flink ) {
805 serr | "\tnode:" | ni | " lnth:" | ni->lnth | " s:" | (void *)ni->s | ",\"";
806 for ( i; ni->lnth ) {
807 serr | ni->s[i];
808 } // for
809 serr | "\" flink:" | ni->flink | " blink:" | ni->blink | nl;
810 } // for
811 serr | nlOn;
812 }
813 serr | "exit:AddThisAfter";
814#endif // VbyteDebug
815} // AddThisAfter
816
817
818// Delete the current HandleNode node.
819
820static void DeleteNode( HandleNode & this ) with(this) {
821#ifdef VbyteDebug
822 serr | "enter:DeleteNode, this:" | &this;
823#endif // VbyteDebug
824 flink->blink = blink;
825 blink->flink = flink;
826#ifdef VbyteDebug
827 serr | "exit:DeleteNode";
828#endif // VbyteDebug
829} // DeleteNode
830
831
832
833// Allocates specified storage for a string from byte-string area. If not enough space remains to perform the
834// allocation, the garbage collection routine is called.
835
836static char * VbyteAlloc( VbyteHeap & this, int size ) with(this) {
837#ifdef VbyteDebug
838 serr | "enter:VbyteAlloc, size:" | size;
839#endif // VbyteDebug
840 uintptr_t NoBytes;
841 char *r;
842
843 NoBytes = ( uintptr_t )EndVbyte + size;
844 if ( NoBytes > ( uintptr_t )ExtVbyte ) { // enough room for new byte-string ?
845 garbage( this, size ); // firer up the garbage collector
846 verify( (( uintptr_t )EndVbyte + size) <= ( uintptr_t )ExtVbyte && "garbage run did not free up required space" );
847 } // if
848 r = EndVbyte;
849 EndVbyte += size;
850#ifdef VbyteDebug
851 serr | "exit:VbyteAlloc, r:" | (void *)r | " EndVbyte:" | (void *)EndVbyte | " ExtVbyte:" | ExtVbyte;
852#endif // VbyteDebug
853 return r;
854} // VbyteAlloc
855
856
857// Adjusts the last allocation in this heap by delta bytes, or resets this heap to be able to offer
858// new allocations of its original size + delta bytes. Positive delta means bigger;
859// negative means smaller. A null return indicates that the original heap location has room for
860// the requested growth. A non-null return indicates that copying to a new location is required
861// but has not been done; the returned value is the old heap storage location; `this` heap is
862// modified to reference the new location. In the copy-requred case, the caller should use
863// VbyteAlloc to claim the new space, while doing optimal copying from old to new, then free old.
864
865static char * VbyteTryAdjustLast( VbyteHeap & this, int delta ) with(this) {
866
867 if ( ( uintptr_t )EndVbyte + delta <= ( uintptr_t )ExtVbyte ) {
868 // room available
869 EndVbyte += delta;
870 return 0p;
871 }
872
873 char *oldBytes = StartVbyte;
874
875 NoOfExtensions += 1;
876 CurrSize *= 2;
877 StartVbyte = EndVbyte = TEMP_ALLOC(char, CurrSize);
878 ExtVbyte = StartVbyte + CurrSize;
879
880 return oldBytes;
881}
882
883
884// Move an existing HandleNode node h somewhere after the current HandleNode node so that it is in ascending order by
885// the address in the byte string area.
886
887static void MoveThisAfter( HandleNode & this, const HandleNode & h ) with(this) {
888#ifdef VbyteDebug
889 serr | "enter:MoveThisAfter, this:" | & this | " h:" | & h;
890#endif // VbyteDebug
891 verify( h.ulink != 0p );
892 verify( this.ulink == h.ulink );
893 if ( s < h.s ) { // check argument values
894 // serr | "VbyteSM: Error - Cannot move byte string starting at:" | s | " after byte string starting at:"
895 // | ( h->s ) | " and keep handles in ascending order";
896 // exit(-1 );
897 verify( 0 && "VbyteSM: Error - Cannot move byte strings as requested and keep handles in ascending order");
898 } // if
899
900 HandleNode *i;
901 for ( i = h.flink; i->s != 0 && s > ( i->s ); i = i->flink ); // find the position for this node after h
902 if ( & this != i->blink ) {
903 DeleteNode( this );
904 AddThisAfter( this, *i->blink );
905 } // if
906#ifdef VbyteDebug
907 {
908 serr | "HandleList:";
909 serr | nlOff;
910 for ( HandleNode *n = HeaderPtr->flink; n != HeaderPtr; n = n->flink ) {
911 serr | "\tnode:" | n | " lnth:" | n->lnth | " s:" | (void *)n->s | ",\"";
912 for ( i; n->lnth ) {
913 serr | n->s[i];
914 } // for
915 serr | "\" flink:" | n->flink | " blink:" | n->blink | nl;
916 } // for
917 serr | nlOn;
918 }
919 serr | "exit:MoveThisAfter";
920#endif // VbyteDebug
921} // MoveThisAfter
922
923
924
925
926
927//######################### VbyteHeap #########################
928
929// Compare two byte strings in the byte-string area. The routine returns the following values:
930//
931// 1 => Src1-byte-string > Src2-byte-string
932// 0 => Src1-byte-string = Src2-byte-string
933// -1 => Src1-byte-string < Src2-byte-string
934
935int ByteCmp( char *Src1, int Src1Start, int Src1Lnth, char *Src2, int Src2Start, int Src2Lnth ) {
936#ifdef VbyteDebug
937 serr | "enter:ByteCmp, Src1Start:" | Src1Start | " Src1Lnth:" | Src1Lnth | " Src2Start:" | Src2Start | " Src2Lnth:" | Src2Lnth;
938#endif // VbyteDebug
939 int cmp;
940
941 CharZip: for ( int i = 0; ; i += 1 ) {
942 if ( i == Src2Lnth - 1 ) {
943 for ( ; ; i += 1 ) {
944 if ( i == Src1Lnth - 1 ) {
945 cmp = 0;
946 break CharZip;
947 } // exit
948 if ( Src1[Src1Start + i] != ' ') {
949 // SUSPECTED BUG: this could be be why Peter got the bug report about == " " (why is this case here at all?)
950 cmp = 1;
951 break CharZip;
952 } // exit
953 } // for
954 } // exit
955 if ( i == Src1Lnth - 1 ) {
956 for ( ; ; i += 1 ) {
957 if ( i == Src2Lnth - 1 ) {
958 cmp = 0;
959 break CharZip;
960 } // exit
961 if ( Src2[Src2Start + i] != ' ') {
962 cmp = -1;
963 break CharZip;
964 } // exit
965 } // for
966 } // exit
967 if ( Src2[Src2Start + i] != Src1[Src1Start+ i]) {
968 cmp = Src1[Src1Start + i] > Src2[Src2Start + i] ? 1 : -1;
969 break CharZip;
970 } // exit
971 } // for
972#ifdef VbyteDebug
973 serr | "exit:ByteCmp, cmp:" | cmp;
974#endif // VbyteDebug
975 return cmp;
976} // ByteCmp
977
978
979// The compaction moves all of the byte strings currently in use to the beginning of the byte-string area and modifies
980// the handles to reflect the new positions of the byte strings. Compaction assumes that the handle list is in ascending
981// order by pointers into the byte-string area. The strings associated with substrings do not have to be moved because
982// the containing string has been moved. Hence, they only require that their string pointers be adjusted.
983
984void compaction(VbyteHeap & this) with(this) {
985 HandleNode *h;
986 char *obase, *nbase, *limit;
987
988 NoOfCompactions += 1;
989 EndVbyte = StartVbyte;
990 h = Header.flink; // ignore header node
991 for () {
992 memmove( EndVbyte, h->s, h->lnth );
993 obase = h->s;
994 h->s = EndVbyte;
995 nbase = h->s;
996 EndVbyte += h->lnth;
997 limit = obase + h->lnth;
998 h = h->flink;
999
1000 // check if any substrings are allocated within a string
1001
1002 for () {
1003 if ( h == &Header ) break; // end of header list ?
1004 if ( h->s >= limit ) break; // outside of current string ?
1005 h->s = nbase + (( uintptr_t )h->s - ( uintptr_t )obase );
1006 h = h->flink;
1007 } // for
1008 if ( h == &Header ) break; // end of header list ?
1009 } // for
1010} // compaction
1011
1012
1013static double heap_expansion_freespace_threshold = 0.1; // default inherited from prior work: expand heap when less than 10% "free" (i.e. garbage)
1014 // probably an unreasonable default, but need to assess early-round tests on changing it
1015
1016void TUNING_set_string_heap_liveness_threshold( double val ) {
1017 heap_expansion_freespace_threshold = 1.0 - val;
1018}
1019
1020
1021// Garbage determines the amount of free space left in the heap and then reduces, leave the same, or extends the size of
1022// the heap. The heap is then compacted in the existing heap or into the newly allocated heap.
1023
1024void garbage(VbyteHeap & this, int minreq ) with(this) {
1025#ifdef VbyteDebug
1026 serr | "enter:garbage";
1027 {
1028 serr | "HandleList:";
1029 for ( HandleNode *n = Header.flink; n != &Header; n = n->flink ) {
1030 serr | nlOff;
1031 serr | "\tnode:" | n | " lnth:" | n->lnth | " s:" | (void *)n->s | ",\"";
1032 for ( i; n->lnth ) {
1033 serr | n->s[i];
1034 } // for
1035 serr | nlOn;
1036 serr | "\" flink:" | n->flink | " blink:" | n->blink;
1037 } // for
1038 }
1039#endif // VbyteDebug
1040 int AmountUsed, AmountFree;
1041
1042 AmountUsed = 0;
1043 for ( HandleNode *i = Header.flink; i != &Header; i = i->flink ) { // calculate amount of byte area used
1044 AmountUsed += i->lnth;
1045 } // for
1046 AmountFree = ( uintptr_t )ExtVbyte - ( uintptr_t )StartVbyte - AmountUsed;
1047
1048 if ( ( double ) AmountFree < ( CurrSize * heap_expansion_freespace_threshold ) || AmountFree < minreq ) { // free space less than threshold or not enough to serve cur request
1049
1050 extend( this, max( CurrSize, minreq ) ); // extend the heap
1051
1052 // Peter says, "This needs work before it should be used."
1053 // } else if ( AmountFree > CurrSize / 2 ) { // free space greater than 3 times the initial allocation ?
1054 // reduce(( AmountFree / CurrSize - 3 ) * CurrSize ); // reduce the memory
1055
1056 // `extend` implies a `compaction` during the copy
1057
1058 } else {
1059 compaction(this); // in-place
1060 }// if
1061#ifdef VbyteDebug
1062 {
1063 serr | "HandleList:";
1064 for ( HandleNode *n = Header.flink; n != &Header; n = n->flink ) {
1065 serr | nlOff;
1066 serr | "\tnode:" | n | " lnth:" | n->lnth | " s:" | (void *)n->s | ",\"";
1067 for ( i; n->lnth ) {
1068 serr | n->s[i];
1069 } // for
1070 serr | nlOn;
1071 serr | "\" flink:" | n->flink | " blink:" | n->blink;
1072 } // for
1073 }
1074 serr | "exit:garbage";
1075#endif // VbyteDebug
1076} // garbage
1077
1078#undef VbyteDebug
1079
1080
1081
1082// Extend the size of the byte-string area by creating a new area and copying the old area into it. The old byte-string
1083// area is deleted.
1084
1085void extend( VbyteHeap & this, int size ) with (this) {
1086#ifdef VbyteDebug
1087 serr | "enter:extend, size:" | size;
1088#endif // VbyteDebug
1089 char *OldStartVbyte;
1090
1091 NoOfExtensions += 1;
1092 OldStartVbyte = StartVbyte; // save previous byte area
1093
1094 CurrSize += size > InitSize ? size : InitSize; // minimum extension, initial size
1095 StartVbyte = EndVbyte = TEMP_ALLOC(char, CurrSize);
1096 ExtVbyte = (void *)( StartVbyte + CurrSize );
1097 compaction(this); // copy from old heap to new & adjust pointers to new heap
1098 free( OldStartVbyte ); // release old heap
1099#ifdef VbyteDebug
1100 serr | "exit:extend, CurrSize:" | CurrSize;
1101#endif // VbyteDebug
1102} // extend
1103
1104//WIP
1105#if 0
1106
1107// Extend the size of the byte-string area by creating a new area and copying the old area into it. The old byte-string
1108// area is deleted.
1109
1110void VbyteHeap::reduce( int size ) {
1111#ifdef VbyteDebug
1112 serr | "enter:reduce, size:" | size;
1113#endif // VbyteDebug
1114 char *OldStartVbyte;
1115
1116 NoOfReductions += 1;
1117 OldStartVbyte = StartVbyte; // save previous byte area
1118
1119 CurrSize -= size;
1120 StartVbyte = EndVbyte = new char[CurrSize];
1121 ExtVbyte = (void *)( StartVbyte + CurrSize );
1122 compaction(); // copy from old heap to new & adjust pointers to new heap
1123 delete OldStartVbyte; // release old heap
1124#ifdef VbyteDebug
1125 serr | "exit:reduce, CurrSize:" | CurrSize;
1126#endif // VbyteDebug
1127} // reduce
1128
1129
1130#endif
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